The present invention relates to a novel boat steering mechanism, and more particularly to a boat steering mechanism in which a push-pull control cable is led out of the center or its vicinity, in the longitudinal direction, of a rack and cable assembly, whereby the push-pull control cable can be provided with a large curvature, and which has a simple structure.
Hitherto, there is on the market a boat steering mechanism which can control a remotely mounted rudder by means of a push-pull control cable, which is suggested by U.S. Pat. No. 3,208,300. As shown in FIGS. 6 to 8, the steering mechanism comprises a pinion 22 secured to a steering wheel shaft 21, a rack 23 the teeth of which mesh with teeth of the pinion 22, an inner cable 24 of the push-pull control cable which is connected to one end of the rack 23 and a rack cartridge 25 for slidably guiding and receiving the rack 23. The steering mechanism translates the rotative motion of a steering wheel 26 into the linear motion of the inner cable 24 of the push-pull control cable by means of the pinion 22 and the rack 23, whereby the steering mechanism can control a remotely mounted rudder.
In the above-mentioned boat steering mechanism, the inner cable 24 is slidably pushed and pulled in an outer casing 27 by the application of either tensile or compressive forces. The inner cable 24 must be guided so as to not bend in the rack cartridge 25 by the compressive force. Therefore, as shown in FIG. 8, it requires that a rod 28, which does not need a guide member even in the application of compressive forces, is connected to one end of the inner cable 24. Also, it requires that a guide pipe 29 for guiding the inner cable 24 extended from the outer casing 27 is extended from the inside of the outer casing 27 of the rack cartridge 25. The boat steering mechanism of the above-mentioned construction has a disadvantage that a complicated construction is necessitated because of requiring the rod 28 and the guide pipe 29, and because of the telescoping arrangement of the rod 28, the guide pipe 29 and the rack 23. Also, the boat steering mechanism has another disadvantage that large resistance is generated between the rack 23 and the guide pipe 29 and between the rod 28 and the guide pipe 29 due to sliding friction. Also, the boat steering mechanism has the other disadvantage that since a member 30 for fixing the outer casing 27 of the control cable is fastened to one end of the rack cartridge 25, the length of the rack cartridge 25 becomes longer in a longitudinal direction. When using the boat steering mechanism in the narrow space of a boat, the curvature of the curved portion in the push-pull control cable has a small radius as shown in FIG. 6. Therefore, the boat steering mechanism has the further disadvantage that the sliding resistance of the inner cable becomes larger.